Download
1 / 23
230 likes | 400 Views
授課老師：吳文海 學 生：林姍虹 報告日期： 2010/12/21. INTRODUCTION. 奈米磁性粒子 的應用： 生物醫療感測器、生物分離、熱療、 藥物輸送 、標靶治療等。 本研究所用的 PLGA 合成聚合物比天然聚合物具有 高純度 和 再現性 的優勢， 且具有 生物 相 容性 及 良好的 生物降解 。 磁性聚合物合成的方法有 bottom-up technique 、 top-down technique 等 。
E N D
授課老師：吳文海 學 生：林姍虹 報告日期：2010/12/21
INTRODUCTION • 奈米磁性粒子的應用：生物醫療感測器、生物分離、熱療、藥物輸送、標靶治療等。 • 本研究所用的PLGA合成聚合物比天然聚合物具有高純度和再現性的優勢，且具有生物相容性及良好的生物降解。 • 磁性聚合物合成的方法有 bottom-up technique、top-down technique等。 • 奈米顆粒的形成是利用top-down technique 是由疏水性、親水性相互作用，以及離子和凡得瓦爾力，而非聚合、交聯反應， • 本研究以乳化蒸發法製備奈米粒子包埋磁性物質，並探討不同條件下粒徑之改變，並利用TGA、TEM、DLS分析其性質。
MATERIALS • Oleic acid • Hydrochloric acid • Iron oxide • Potassium Ferrocyanide
MATERIALS • Poly(D,L-lactide-co-glycolide) (PLGA) • Ethyl acetate • Sodium dodecyl sulfate(SDS)
NANOPARTICLES PREPARATION • MAGNETITE 將Iron oxide &Potassium Ferrocyanide加入過量的鹼 利用共沉澱法製造出MAGNETITE
NANOPARTICLES PREPARATION • HYDROPHOBIC MAGNETITE 15ml水溶液( 20%Oleic acid &10%ammonium hydroxide) 加入MAGNETITE 攪拌30min ，80 ℃(在油浴中) 清洗三次 使用氮氣乾燥2h，可得到MOA
NANOPARTICLES PREPARATION • SINGLE EMULSION EVAPORATION WITH HYDROPHOBICMAGNETITE 125mg PLGA溶解於2.5ml ethyl acetate (形成油相) 加入MOA，超音波震盪10 min 注入SDS水相溶液(油相跟水相體積百分比1:4) 冰浴中，放入均質機2min(轉速12000rpm)
NANOPARTICLES PREPARATION 超音波震盪10min 使用鼓式蒸發器7min 使用透析純化法清洗，共洗四次 奈米微粒預凍－80℃ 、 3h 冷凍乾燥法48h、－41 ℃
TEM-MOA Fig. 1. Surface modified magnetite with oleic acid (MOA). (A) Individual MOA nanoparticle size was around 15 nm. (B) The appearance of clustering was observed by TEM, in agreement with the DLS data (mean size of 255±35 nm).
TGA- MOA&MAGNETITE 油酸改質後的MOA重量損失較多 Fig. 2. TGA data for magnetite and MOA(magnetite plus oleic acid). The initial decrease in weight was due to the presence of water (approximately 2wt% for magnetite and 1.15% for MOA).
TEM-不同比例MOA • Fig. 3. Magnetic–polymeric nanoparticles with medium molecular weight PLGA. • 4% (w/w) MOA theoretical loading. • 8% (w/w) MOA theoretical loading. • The black particles represent MOA entrapped in the PLGA nanoparticle and MOA surrounded by PLGA nanoparticles (all M-P NPs TEM pictures were not mixed with a contrast agent).
TEM-PLGA包覆MOA Fig. 4. (A) Magnetic–polymeric nanoparticle with medium molecular weight PLGA (40–75 kDa) and 4% MOA theoretical loading, which shows MOA entrapped in the PLGA matrix. (B) Polymeric nanoparticle with medium PLGA molecular weight (sample was mixed with uracyl acetate at 2% as a contrast agent).
SDS不同濃度之影響： 界面活性劑濃度越高粒徑越小，濃度約5mg/ml時，粒徑趨於穩定。 Fig. 5. Effect of SDS concentration on the size and polydispersity index of PLGA nanospheres
PLGA濃度與SDS濃度的影響： 界面活性劑濃度較高時，PLGA粒徑改變不明顯。 Fig. 6. Effect of PLGA concentration and SDS concentration on the nanoparticle size
不同PLGA分子量之影響： Table 1 Size of PLGA nanoparticles without magnetite entrapped in the polymeric matrix 分子量越小，粒徑越小 隨分子量改變，PI沒有明顯變化 表面帶負電荷可以避免粒子聚集
超音波震盪之影響： Table 2 Effect of pre-sonication time of MOA on the PLGA nanoparticles size with magnetite entrapped in the polymeric matrix MOA pre-sonication refers to sonication of the organic phase formed with PLGA,MOA, and ethyl acetate for 2, respectively, for 10min. Following the emulsification step, the samples were further sonicated for 10min to reduce the emulsion droplet size, n =3.
不同分子量之分佈影響： Fig. 7. PLGA nanoparticles size and polydispersity measured by DLS (at 25◦C,n = 3).
分子量與MOA不同濃度之粒徑影響： Table 3 Entrapment of magnetite oleic acid and SDS residue in nanoparticles n =3. A Theoretical loading: initial amount of MOA added to the nanoparticle formation process (wt%). B Nanosphere yield: final weight of sample after freeze drying (mg)/initial weight of sample (mg). C Entrapment efficiency: MOA in samples (wt%)/theoretical loading (wt%). D SDS residue: total residue (wt%) (from TGA)–magnetite (wt%) (from colorimetric method). E SDS removed: SDS residue (wt%)/total SDS added in the nanoparticle formation process (wt%).
TGA-SDS Fig. 8. SDS profiles acquired by TGA. Temperature was varied from 25 to 600 ◦C. A residue of 24.75% composed of sulfate and sodium group of the SDS molecule was found at 600 ◦C.
CONCLUSIONS • 利用油酸作表面改質使包埋的magnetite成疏水聚合物，具有高包埋率。 • 提高MOA的含量4%→8% ，粒徑100nm→120nm。 • PLGA分子量越高，MOA包埋率越高。 • SDS濃度可控制奈米粒子的大小，當界面活性劑濃度越高，粒徑越小。 • 超音波震盪是另一個是影響奈米磁性粒子大小和粒度分佈的重要因素，震盪時間較久的粒徑及分佈都較小。
